const initState = 0;
function count_Reducer(preState = initState, action) {
  console.log(preState, action);
  const { data, type } = action;
  switch (type) {
    case "increment":
      return data + preState;
    case "decrement":
      return preState - data;
    default:
      // 初始化
      return preState;
  }
}
export default count_Reducer;
